In general, the signal transformation structure of a computer motherboard and computer peripheral devices (for example, hard disk drivers and optic disk drivers) is achieved by the matching between a cable (flat cable) and connectors. The matching between the flat cable and connectors are widely used in the technology. In general, a cable assembly is formed by a flat cable and three approximately identical connectors. The three connectors serve to be connected with the terminal connectors of for example a motherboard, a hard disk driver, and an optic disk driver so that the signals in the three active devices may be communicate d through the flat cable. Conventionally, the connector matching with this flat cable generally has a positioning cover, an insulating body, terminals (signal terminals and grounding terminals) and others. In assembly, the positioning cover and the insulating body are combined firstly for forming a space, and then the flat cable is inserted into the space. Then, a fixture serves to press the positioning cover downwards so as to be combined with the insulating body. As the positioning cover is pressed downwards, a piercing terminal within the inserting hole of the insulating body terminal will pierce the insulated skin of the flat cable so as to contact with the central wire of the conductor within the flat cable. In some prior art, in order to avoid the flat cable contacting with the terminal is pulled to form an ill contact. Therefore, a pressing cover is further provided. The function of the pressing cover is that when the flat cable bends upwards from below the positioning cover to above the positioning cover, the pressing cover presses the positioning cover combined with the insulating body for avoiding loosening between the flat cable and the terminals.
The aforesaid flat cable connector has been disclosed in U.S. Pat. Nos. 4,359,257, 5,104,336, 5,417,584, and 5,509,195 and Taiwan Patent Nos. 82200254, 81105296, 86213505, 85218513 and 86214200.
Recently, with the increase of the amount of signal transfer and transferring speed, the flat cable tends to a high density design. Namely, the gaps in the slender lines of the flat cable are reduced and the number of the slender lines are increased. Since the high density of the flat cable, in order to insure that no noise interruption will occur in the process of signal transformations between the three active devices, the signal wires and the grounding wires are arranged alternatively for being connected to the signal terminals and the grounding terminals, respectively. In some applications, some specific signal wires of the flat cable must be further connected to the grounding terminals for filtering noises. In some cases, one specific signal wire must be connected to the grounding terminal (for example first connector connected to the motherboard) in the cable assembly but not electrically connected to any connector (for example the second connector and third connector for being connected respectively to a hard disk driver and an optic disk driver) of the cable assembly. In other words, the specific signal wire must be connected with the grounding piece of the first connector, and signals will be transferred between the second connector and the third connector but not transferred to the first connector.
For the aforesaid special case, a specific conductive wire is connected to the signal terminal and grounding terminal of the first connector and then a small notch is formed in the signal wire (i.e. forming an open circuit) so that the portion of the conductive wire after the notch is still in contact with the second connector and third connector, but not conductively connected with the first connector.
However, in the prior art for the special case, the grounding piece of the first connector must have some difference from the second connector and the third connector. Therefore, in manufacturing the grounding piece, at least two grounding piece punching molds are necessary, one for manufacturing the grounding piece having grounding terminal (for first connector) with respect to the No. 34 signal wire, and another for the grounding piece without grounding terminal (for second connector and third connector) with respect to the No. 34 signal wire. This increases cost, and, since the differences between the two grounding pieces are very slight, some improper assembly risks are incurred. Moreover, the notch in the specific signal wire causes difficulty in assembly.